Rheostat with switch



y 1949. J. G. KUNZ, JR 2,469,924

RHEOSTAT WITH SWITCH I Filed Feb. 6, 1947 2 Sheets-Sheet 1 May "M 1949. J. a. KUNZ, JR

RHEOSTAT WITH SWITCH 2 Sheets-Sheet 2 Filed Feb. 6, 1947 Fig. 7.

Fig.8.

, Inventor John G Kunz, Jr.

W .l/ I u time]:

Patented May 10, 1949 UNITED STATES PATENT OFFlCE RHEOSTAT WITH SWITCH John G. Kunz, Jr., Battle Ground, Wash. Application February 6, 1947, Serial No. 726,929 (01. 201-55) 16 Claims. 1

The present invention relates to new and useful improvements in circuit controlling devices and more particularly to a unitary switch and 'rheostat construction for controlling relatively low voltage circuits.

An important object of the present invention is to provide a rheostat having a control switch including a knob for operating the switch and having a lamp therein which becomes energized when the switch is closed.

Another object of the invention is to provide locking means for the rheostat arm when the switch is in its open position;

A further object is to provide means to indicate by the brilliancy of the lamp the amount of current entering the circuit.

A still further object is to provide a device of this character of simple and practical construction, which is efllcient and reliable in operation, relatively inexpensive to manufacture and otherwise well adapted for the purposes for which the same is intended.

Other objects and advantages reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a longitudinal sectional view of one form of the invention;

Figure 2 is a sectional view taken on the line 2-2 of Figure l;

Figure 3 is a similar view taken on the line 33 of Figure 1;

Figure 4 is a longitudinal sectional view of a modified construction including a lamp for the switch;

Figure 5 is a perspective view of the outer rotatable barrel connecting the knob of the switch to the rheostat contact arm;

Figure 6 is a longitudinal sectional view of the invention showing a lock for the switch;

Figure 7 is a fragmentary longitudinal sec 'tional view of a modified lock construction;

Figure 8 is a longitudinal sectional view of another modified iorm of the invention and showing a rheostat control for the lamp, and

Figure 9 is a sectional view taken on the line 9-4 of Figure 8.

.Referring now to the drawings in detail and first with respect to the form of invention illustrated in Figures 1 to 3 inclusive, the numeral 5 designates a hollow cylindrical body constructed of any suitable refractory insulation material and having one end closed as shown at 6. A plug 1 also of suitable insulation material is fitted in the open end of the body and secured therein by screws or the like 8. A reduced externally threaded metallic stem 9 has one end embedded in the plug 1 and projects outwardly from the plug and the plug 1 and extension 9 are provided with a bore l0 extending therethrough, the outer end of the bore in the stem 9 having a key slot ll formed therein.

A rod I2 is slidably and rotatably mounted in the bore lo, the inner end of the rod having a circular block l3 secured thereto and to the periphery of which is secured a conductor ring ll with an annular groove 15 in the periphery of the ring.

A pair of terminals I6 and H in the form of bolts and nuts extend through the closed end 6 of the body and to the inner end of the terminal H5 is secured one end of a resilient contact finger l8 and which has its free end curved as shown at Hi to enter the groove [5 of the conductor ring when the rod i2 is pulled outwardly in the position as shown by the full line in Figure 1.

A circuit wire 20 has one end connected to the terminal i1 and its other end connected to one end of a resistance coil 2! recessed in the inner surface of the plug 1. A resilient rheostat arm 22 projects radially from the conductor ring H at its inner edge and has its free end curved as shown as 23 to travel along the exposed edge of the coil 2| by rotary movement of the rod i2. A stop 24 of insulation material projects from the inner endof the plug 1 for engagement by the arm 22 to prevent jumping of the arm from the high to the low side of the coil and vice versa.

To the outer end of the rod i2 is secured a knob 25 to sli-dably actuate the rod by a pushing and pulling movement of the knob whereby to open and close the switch by moving the conductor ring into or out of engagement with the contact finger iii. A longitudinally extending key 26 is formed on the rod I2 inwardly of the knob 25 which is free of the slot ll when the knob is pulled outwardly and to permit free rotation of the rod and the rheostat arm 22 and the key 26 is adapted to enter the slot II when the knob 25 is pushed inwardly to lock the switch against rotation in its open position.

A pair of nuts 2'! are threaded on the stem 9 of the plug for clamping against opposite sides of a supporting structure to mount the device in position thereto.

In the form of the invention shown in Fi ures 4 and 5 the hollow body is shown at 28, insulation plug at 29 with externally threaded metal stem 38 and attaching nuts 3I, and resistance coil at 32.

An outer barrel 83 is rotatably mounted in the plug 28 and stem 38 to the outer end of which is secured the knob 34. The annular head 85 is secured to the inner end of barrel 33 and which carries the conductor ring 38 and contact arm 81 movable over the coil.

The barrel is formed adjacent each end with outwardly pressed internal grooves 38 in which are seated annular ribs 38 formed on an inner barrel 48 forming a conduit for a circuit wire H which projects from the rear end of barrel 48 through a plug 42 and is connected to contact arm 31. The other end of wire 42 is connected to the base of a lamp socket 43 formed at the front end of barrel 48 and loosely mounted in the knob 84 for contact by the base of a lamp 43a mounted in the socket. The lamp is enclosed in a transparent or translucent cover 44 threaded to the outer end of knob 34.

The lamp is grounded through socket 43, inner barrel 48, outer barrel 83, stem 38 and attaching nuts 8I to a supporting structure.

The inner barrel 48 is held rotatably stationary by a pin 45 projecting radially therefrom and into a longitudinal groove 41 formed in plug 28 to provide for the sliding movement of the barrels in the plug during opening and closing of the switch. The outer barrel 33 is also provided with a circumferential slot 48 to accommodate the pin 45 during rotation of the outer barrel while the pin holds the inner barrel rotatably stationary.

The outer barrel 33 is also provided with a key 48 engaged in a key slot 88 in the stem 38 to lock the switch against rotation when the knob is pushed inwardly.

When the knob is pulled outwardly to close the switch, the brilliance of the lamp 43a will indicate the amount of current entering the circuit in accordance with adjustment of the contact arm 31 on rheostat coil 32 by the rotation of the knob.

Figure 6 illustrates a modified construction or the circuit connection for the lamp during adjustment of the rheostat without danger of twisting the wires during frequent turning of the knob. The hollow body is provided with the usual insulation plug 82, threaded metal stem 83, coil 54 recessed in the plug, knob 88 holding the lamp 56, barrel 5! rotatable in the plug to the outer end of which the knob is carried and to the inner end of which the annular head 88 and conductor ring 58 is carried with the contact finger l8 travelling over the coil.

A conductor plug 8| is suitably secured in a rearwardly projecting position at the inner end of barrel 51 and insulated therefrom and to which a circuit wire is attached leading to the lamp 58 through the barrel. A resilient clip 82 comprising a pair of spring contact fingers 83 is secured to the rear end of body SI and between the free ends of the fingers the plug slides during inward and outward movement of the knob when opening and closing the switch. The clip 82 is electrically connected to the terminal 84 of the circuit.

This construction provides a continuous circuit connection for the lamp during rotation of the head 58 by the turning of knob 85 without danger of twisting the circuit wire.

This form of the invention also includes a locking device for the knob and which comprises a dog 85 pivoted at the inside of barrel 81, one end of the dog being actuated by a push button 88 pivoted to the dog and working through the side of the barrel. The free end of the dog works through an opening 81 in the barrel to enter a recess 88 in the bore of the stem 88 when the knob is pushed inwardly to lock the switch in its open position. A leaf spring 88 carried by the knob has a free end arranged to enter a recess 18 in the push button 88 to secure the push button in its inward position to hold the dog in locked position.

Figure 7 illustrates a further modified construction of the circuit connection for the lamp and shows the hollow body I I, insulation plug I2 having the coil I8 recessed therein and annular head I4 carried at the inner end of barrel I5. The head I4 is provided with the conductor ring I8 having a circumferential groove 11 therein. The circuit wire "I8 for the lamp extends through the barrel and a plug 18 of insulation material is suitably secured in the inner end of the barrel and through which the wire extends for attaching to a concave-convex disk 88 secured against the outer end of the plug 18.

A resilient U-shaped clip 8I having a pair of spring fingers 82 is attached to the inside of body H and a coil spring 88 is held under tension between the clip 8| and disk 88 to hold the head I4 forwardly with the contact finger 84 in engagement with coil 13. A circuit wire 85 connects the spring 83 to the terminal 88 at the rear end of body II.

The spring fingers 82 have inwardly pressed onsets 81 at their ends for entering the groove 11 of conductor ring 16 to hold the switch in its open position.

Figures 8 and 9 show a switch of this character provided with a separate rheostat construction for the lamp 88 mounted in knob 88. A barrel 88 is rotatable in the insulation plug 8| carried by hollow body 82, the barrel connecting the knob to the annular head 83. The head is provided with the conductor ring 84 having a contact finger 88 travelling over coil 88 recessed in plug 8I as heretofore described.

A plug 81 of insulation material is suitably secured in the inner end of barrel 88 and is formed with a socket 88 in which a. head 88 at the rear end of a rod I88 is slidably received with a coil spring I8I in the socket behind the head. The rod extends longitudinally in barrel 88 and is also provided with a head I82 at its front end. A contact I83 is held against the lamp base by a coil spring I84 positioned between head I82 and said contact.

A second relatively smaller rheostat coil I88 is recessed in plug 8| concentric to coil 88 and over which a resilient contact finger I88 travels, said contact finger projecting through an opening III in barrel 88 into the socket 88 behind spring III.

What I claim as my invention is:

1; A circuit controlling device of the class described comprising a cylindrical housing, having an open end, a plug placed in the open end of said housing, a bore extending through the plug and into the housing, a key slot in the outer end of said bore, a shaft slidably and rotatably mounted in the bore, a key extending outwardly from the shaft to engage the key slot in the bore, a resistance coil mounted on the inner surface of the plug, a block mounted on the inner end of the shaft, and a rheostat contact arm carried by the block extending radially across the coil, said arm being movable around the coil by a rotation of the shaft when the shaft is pulled outwardly and said arm being locked against rotaend of the bore, a shaft extending into the bore for sliding and rotating movement, a key extending outwardly from the shaft to engage the key slot in the bore, a resistance coil mounted on the inner surface of the plug, a circular block mounted on the inner end of the shaft, a conductor band encircling the block, and a resistance control arm carried by the band and arranged to travel along the coil when the key of the shaft is pulled out of the key slot of the bore.

3. A circuit controlling device of the class described comprising a cylindrical housing, having an open end, an outlet and inlet terminal carried by the housing, a plug placed in the open end of the housing, a bore extending through the plug and into the housing, a key slot in the outer end of the bore, a shaft extending into the bore for sliding and rotating movement, a key extending radially from the shaft to engage the key slot in the bore and lock the shaft against rotation upon a sliding movement of the shaft in one direction, a resistance coil mounted on the inner surface of the plug, a circular block mounted on the inner end of the shaft, a conductor band encircling the block, a resistance control arm carried by the band and extending radially across the resistance coil when the key is withdrawn from the key slot by a sliding movement of the shaft in an opposite direction, said arm being movable around the coil by a rotation of the shaft, and a resilient contact finger carried by one of the terminals for engaging the band when the shaft is moved to unlocked position.

4. A circuit controlling device comprising a rheostat housing having a resistance coil therein, a shaft slidably and rotatably mounted in the housing and projecting outwardly thereof, a conductor on the inner end of the shaft including a contact finger arranged to travel around the coil by a rotation of the shaft when the shaft is slidably moved in one direction, and interlocking means between the shaft and the housing to secure the shaft against rotation when moved in an opposite direction.

5. A circuit controlling device comprising a rheostat housing having a resistance coil therein, a shaft slidably and rotatably mounted in the housing and projecting outwardly thereof, a conductor on the inner end of the shaft including a contact finger arranged to travel around the coil by a rotation of the shaft when the shaft is slidably moved in one direction, said housing having a key slot, and a key onthe shaft adapted to enter the slot to secure the shaft against rotation when moved in an opposite direction.

6. A circuit controlling device comprising a rheostat housing having a pair of concentrically arranged resistance coils therein electrically connected to each other, a shaft slidably and rotatably mounted in the housing including means to retain a lamp therein, and a pair of resistance control arms carried at the inner end of the shaft and movable over the respective coils by a rotary movement of the shaft, one of said control arm including electrical means for connection to a lamp, both of said control arms being disengaged from the coils by a predetermined sliding movement of the shaft.

7. A circuit controlling device comprising a rheostat housing having a circular resistance coil therein, a hollow shaft slidably and rotatably mounted in the housing and including means to retain a lamp therein, a control arm carried at the inner end of the shaft for movement over the coil by a rotary movement of the shaft, and circuit making and breaking means for engaging a lamp and coil and controlled by a sliding movement of the shaft.

8. A circuit controlling device comprising a rheostat housing having a circular resistance coil therein, a hollow shaft slidably and rotatably mounted in the housing and including means to retain a lamp therein, a control arm carried at the inner end of the shaft for movement over the coil by a rotary movement of the shaft, and a single circuit making and breaking device for engaging a lamp and coil and controlled by a sliding movement of the shaft.

9. A circuit controlling device comprising a rheostat housing having a circular resistance coil therein, a hollow shaft slidably and rotatably mounted in the housing and including means to retain a lamp therein, a control arm carried at the inner end of the shaft for movement over the coil by a rotary movement of the shaft, circuit making and breaking means for engaging a lamp and coil and controlled by a sliding movement of the shaft, and locking means securing the shaft in circuit open position.

10. A circuit controlling device comprising a rheostat housing having a circular resistance coil therein, a hollow shaft slidably and rotatably mounted in the housing and including means to retain a lamp therein, a control arm carried at the inner end of the shaft for movement over the coil by a rotary movement of the shaft, circuit making and breaking means for engaging a lamp and coil and controlled by a sliding movement of the shaft, and automatic locking means securing the shaft in circuit open position.

11. A circuit controlling device comprising a rheostat housing having a circular resistance coil therein, a hollow shaft slidably and rotatably mounted in the housing and including means to retain av lamp therein, a control arm carried at the inner end of the shaft for movement over the coil by a rotary movement of the shaft, circuit making and breaking means for engaging a lamp and coiland controlled by a sliding movement of the shaft, and locking means securing the shaft in circuit open position, said locking means including a pivoted manually operated dog carried by the shaft and engaging a part of the housing.

12. A circuit controlling device of the class described comprising a cylindrical housing, having an open end, a plug placed in the opened end of said housing, a bore extending through the plug and into the housing, a key slot in the outer end of said bore, a shaft slidably and rotatably mounted in the bore, a key extending outwardly from the shaft to engage the key slot in the bore, a resistance coil mounted on the inner surface of the plug, a block mounted on the inner end of the shaft, a rheostat contact arm carried by the block extending radially across the coil, said arm being movable around the coil by a rotation of 1 13. A circuit controlling device comprising a rheostat housing having a resistance coil therein, a shaft slidably and rotatably mounted in the housing and projecting outwardly thereof, a conductor on the inner end of the shaft including a contact finger arranged to travel around the coil by a rotation of the shaft when the shaft is slidably moved in one direction, interlocking means between the shaft and the housing to secure the shaft against rotation when moved in an opposite direction, and a contact finger on the housing engaging said conductor to close the circuit.

14 A circuit controlling device comprising a rheostat housing having a resistance coil therein, a shaft slidably and rotatably mounted in the housing and projecting outwardly thereof, a grooved conductor ring on the inner end of the shaft including a contact finger arranged to travel around the coil by a rotation of the shaft when the shaft is slidably moved in one direction, a contact finger on the housing and including a curved free end engageable in said groove to close the circuit, and interlocking means between the shaft REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,179,686 Cohen Nov. 14, 1939 2,411,891 Owens Dec. 3, 1946 

